AMD-761 Datasheet, PDF (52/264 Pages) Advanced Micro Devices – AMD-761-TM System Controller Software/BIOS Design Guide

Preliminary Information
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Bit Definitions
Bit Name
31–12 Base_Addr_High
11–4 Base_Addr_Low
3 Prefetchable
2–1 Type
0 Memory
Base Address 1: GART Memory-Mapped Register Base (Dev0:F0:0x14)
Function
Base Address High
This bit field forms the upper part of BAR1. This field is loaded by BIOS software.
Base Address Low
This bit field is hardwired to return 0s to indicate that 4 Kbytes are allocated to GART
memory-mapped control registers and that the registers always reside in a 4-Kbyte
boundary per PCI Local Bus Specification, Revision 2.2.
Prefetchable
This bit is hardwired to 1 to indicate that this range is prefetchable
Type
This bit field is hardwired to indicate that this base register is 32 bits wide and mapping
can be performed anywhere in the 32-bit address space.
Memory
This bit is hardwired to 0 to indicate that this base address register maps into memory space.
Programming Notes
40
AMD-761™ System Controller Programmer’s Interface
Chapter 2